How to reproduce : 1. Deploy a webpage ( index.html) on https://www.domain.com/ with the manifest file reference. Config the manifest file as below ( manifest.appcache ): CACHE MANIFEST # Time: Fri Feb 28 2014 11:00:57 GMT+0000 (GMT) CACHE: css/style.css NETWORK: * FALLBACK: / /offline.html Set the webserver to redirect /offline.html to /#/offline.html Result : You get a correct error : Application Cache update failed, because https://www.domain.epek.com/offline.html was redirected. Next : 1. Fix the webserver and handle /offline.html appropriately so that it won't redirect anymore. 2. visit again the webpage Result : You still get the error "Application Cache update failed, because https://www.domain.epek.com/offline.html was redirected." which means that if for some reasons the webserver is malfunctioning and doesn't handle /offline.html file accordingly (e.g. issues a redirect) the clients are punished with a PERMANENT cache.
AppCache is now disabled and will be removed in bug 219391.